Mold.



R. P. LAMONT.

MOLD.

APPLIOA'YIION FILED FEB. 27, 1911.

Patented Nov. 28, 1911.

I mm? ROBERT P. LAMONT, OF" CHICAGO, ILLINOIS.

MOLD.

Specification of Letters Patent.

Patented Nov. 28, 1911.

Application filed February 27, 1911. Serial No. 611,135.

After the pattern has been withdrawn To all whom it may concern: p n

Be it known that I, ROBERT P. LAMONT, a citizen of the United States, residing at Chicago, county of Cook, and State of Illinois, have invented certain new and useful Improvements in Molds, of which the following is a specification.

My invention relates to molds for castings and has particular reference to means associated with the mold cavity whereby the said mold is freely vented at every point.

An object in the manufacture of castings and particularly steel castings is the production of a finished article which shall be free. from blow-holes, pipes and segregated metalloids and this is best accomplished by providing a large number of vents at difi'erent points over the area of the mold cavity. This is objectionable because of the labor necessary in preparing these vents and in removing the risers which are formed therein. I have therefore conceived the idea of making substantially the entire upper portion of the mold cavity of a perforated body and having no sand cope whatever. Of course, in the case of some castings of irregular contour it may be impracticable to form the entire cope of a perforated material and some portions thereof may be formed of sand. It is contemplated that after the metal has set and the casting is re moved from the mold the perforated plate may be easily removed from the casting and adapted for reuse.

I have shown my invention as applied to a mold for making a simple casting but it will be understood that this is only one of the numerous articles which may be produced thereby.

My invention will be more readily understood by reference to the accompanying drawings wherein Figure 1 is a plan view of an embodiment of my invention, a portion of the perforated member being broken away; and Fig. 2 is a section through the mold on the line 2-2 of Fig. 1.

Referring more particularly to the drawing it will be seen that I provide a drag 10 on which is placed a flask 11 containing a body of molding material 12. Arnold cavity is formed in this material by means of the usual pattern. In the embodiment shown, the entire mold cavity is in the drag and is not divided as is necessary in some cases owing to the contour of the pattern.

from the sand the mold cavity is coveredv with a plate 13 of metal or other suitable material and containing, at least over the mold cavity a plurality of perforations 14. Preferably these perforations are of small diameter and may be in close proximity to each other as shown in the drawing or may be more separated.

In the drawing a circular casting 15 in the form of a wheelis shown as having been formed in the mold, the metal having been poured into the mold through the pouring gate 16.

It will be found in practice that the metal will fill the mold cavity and as it comes into contact with the superposed cold material it will freeze thereagainst none of the molten metal rising in the interstices. The material preferably used to form the cope will have a high coeflicient of heat conductivity. The desired result may be attained by the use of iron or steel although a silicious material is also contemplated. However, the mold cavity being in communication with the atmosphere at all points will permit the free venting of the mold and preclude the forming of blow-holes in the casting.

As before stated, after the casting is cooled sufficiently it is removed from the mold and the perforated member stripped therefrom.

It will be understood that the perforations 14 are somewhat exaggerated in the drawings for the sake of clearness. It may be found preferable to limit the size and increase the number of perforations.

It will be understood that although I have shown my invention in connection with a specific form of perforated plate and as applied to a specific form of casting, the invention is adapted for use in connection with many modified forms of construction other than herein shown and described.

I claim:

1. A mold for making castings comprising, in combination, a body of molding material containing. a mold cavity, and a plate associated with said cavity and adapted to form one wall thereof, said plate containing alarge number of relatively small perforations.

2. A mold for making castings comprising, in combination, a drag and a cope, a body of molding material therein, said molding material containing a mold cavity, said cope being formed of metal of relatively cavity, said cope being of relatively thin 10 section and having a high co-eiiicient of heat conductivity and containing a large number of relatively small perforations, substantially as described.

ROBERT P. LAMONT. Vitnesses S. M. DARLING, CHAS. F. MURRAY.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, .D. C. 

